Locked bead pneumatic tire with wrap-around toeguard

ABSTRACT

A pneumatic tire  10  has a carcass ply  12  or plies  12, 14  with a locked tie-in construction and a wrap-around toeguard  18.  Each wrap-around toeguard  18  is a non cord reinforced elastomeric unitary strip wound 360 degree in a singular annular bead. The wrap-around toeguard cord reinforced unitary strip  18  can be formed of a single elastomeric composition having a shore hardness D of greater than 40. Alternatively the wrap-around toeguard may additionally include an apex portion  29  and a chafer portion  27  along with the toeguard portion  28 , each portion  27, 29  being co-extruded or otherwise hot formed and shaped with the toeguard portion  28  to form the unitary strip  18  and can have distinct elastomeric composition relative to the toeguard portion  28.

FIELD OF THE INVENTION

The present invention relates to a pneumatic tire having a carcassreinforced with a high ending turnup and a locked bead construction.

BACKGROUND OF THE INVENTION

The desirability of having the turnup portions of the carcass ply (orplies) of a pneumatic tire extend radially outwardly of the bead corethe shortest possible distance is the premise on which prior art lockedbeads were developed. The proposed advantages included improved beaddurability, and reduced material costs.

U.S. Pat. No. 4,922,985, issued May 8, 1990, discloses a carcass plyhaving a main portion that extends between both bead cores (not shown)of the tire and turnup portions that are anchored around each bead core.Tires according to U.S. Pat. No. 4,922,985 have the radially outer edgesof the turnup portions of the carcass ply disposed radially outwardly ofthe bead cores a minimal distance and are in contact with the mainportion of the carcass ply. Suitable elastomeric materials surround thebead core, carcass ply and other elastomeric components to complete thebead portion of the tire. In FIG. 4 of this patent, there is illustrateda clamping member comprised a strip of side-by-side cords of a heatshrinkable material embedded in a suitable elastomeric substance havinga permanent thermal shrinkage of at least 2 percent. This strip of cordsextended from a location radially and axially inward of the bead core toa location radially outward of the bead core and there was no fillerstrip or apex disposed between the main portion and turnup portion ofthe carcass ply.

Tires according to U.S. Pat. No. 4,922,985 were manufactured using aclamping member in which the heat shrinkable material was 1260/2 Nylon6,6, having a permanent thermal shrinkage of about 4 percent. It iscontinually the goal in the art to simplify the construction and reducethe expense of building tires, yet improve the durability, handling,rolling resistance and other properties of tires.

In U.S. Pat. Nos. 5,524,688 and 6,719,030 pneumatic tires had twocarcass plies or a single carcass ply reinforced with metallic cords,respectively. Each tire had a high ending ply turnup and locked beadconstruction.

The pneumatic tire 100 of U.S. Pat. No. 6,719,030 as shown in FIG. 7 hada single carcass ply 12 reinforced with parallel metallic cords, eachcord composed of at least one filament having a tensile strength of atleast (−2000.times.D+4400 MHa).times.95%, where D is the filamentdiameter in millimeters. The turnup portion of the single carcass ply inthe bead portion of a pneumatic tire was interposed between the beadcore and a toe guard, and the radially outer edge of each turnup portionbeing in contact with the main portion of the carcass ply and extendingto an end point 0.5 to 4.0 inches (12.7 to 101.6 mm) radially outward ofthe bead core. The toe guard had a first and second end and each end wasdisposed directly adjacent to the carcass ply. The first end of the toeguard was located on the axially inner side of the main portion of thecarcass ply at a location about 0.4 to 3.5 inches (10 to 89 mm) radiallyoutward of the bead core and the second end was located at a pointranging from substantially the axially outermost point of the bead coreto a location about 3.5 inches (89 mm) radially outward of the beadcore. The first end and second end of the toe guard was a shorterdistance from the bead core than the end point of the turnup portion ofthe carcass ply.

The toe guard may be a rubber material, a flexible textile material or aheat shrinkable material. For example, according to the embodimentillustrated in FIG. 7, the toeguard comprised a strip of side-by-sidecords of a non-metallic heat shrinkable material which has a permanentthermal shrinkage of at least 2 percent wrapped circumferentially aboutthe bead core and carcass ply turnup a plurality of times.

When the toeguard was disclosed as a rubber material it was disclosed tobe canlendered gum strips circumferentially wound around the bed coreand carcass ply turnups a plurality of times.

The use of separate stiffeners or apexes and chafer strips were shown tobe used in combination with the plurality of windings of the gum stripused in the toeguard to form the bead portion of the tire.

The uses of multiple windings of strip of material wound around thegreen or uncured tire to form a carcass in cylindrical form can lead tovariations in the rubber thicknesses and gauges around the circumferenceof the tire as it is shaped toroidally and placed in a mold to cureunder temperature and pressure. In particular the area directly underthe bead core. These anomalies can create mass imbalances andnon-concentric positioning of the tire structure when mounted onto arim, this resulting in undesirable force variations in tire as itrotates.

The present invention provides a novel way to eliminate the number ofstrips or rubber components in the bead portion of a tire using anon-cord reinforced toeguard.

The present invention by employing a unitary structure eliminates thenon-uniformities created by the use of multiple strips of elastomericcomponents around the bead.

Thin and thick sections under the bead core and entrapped air problemsassociated with the use of multiple windings having step offs whichcreate air pockets is eliminated in the tire bead area of the presentinvention tire.

SUMMARY OF THE INVENTION

A pneumatic tire has a pair of axially spaced apart annular bead cores,at least one cord reinforced carcass ply wrapped around each bead coreand having at least one pair of carcass ply turnups substantiallycontiguous with the at least one carcass ply from the bead core to aradially outer end or ends of the at least one pair of carcass plyturnups; and a wrap-around toeguard associated with each bead core. Eachwrap-around toeguard is a non-cord reinforced elastomeric unitary stripwound 360° in a single annular loop. Each wrap-around toeguard has firstand second ends wherein each end thereof is disposed directly adjacentto said carcass ply. The first end is located on the axially inner sideof the carcass ply at a location about 0.4 inches (10 mm) to 3.5 inches(89 mm) radially outward of the bead core as measured along the carcassply. The second end is adjacent the turnup of the carcass ply located ata point ranging from substantially the axially outermost point of thebead core to a location about 3.5 inches (89 mm) radially outward of thebead core as measured along the turnup of the carcass ply. The first endand second end of the toeguard are a shorter radial distance from saidbead core than a radially outermost end of the at least one turnup ofthe at least one carcass ply.

In one embodiment a radially inner portion of the second end of thewrap-around toeguard extends from the bead core and the turnup axiallyoutwardly to the outer surface tire. The radially outer portion of thesecond end of the wrap-around toeguard is overlapped by a radially innerend portion of the sidewall of the tire.

The wrap-around toeguard can be a non-cord reinforced unitary extrudedor otherwise shaped strip having a predetermined cross sectional shapeformed of a single elastomeric composition having a shore D hardnessgreater than 40.

Alternatively, the wrap-around toeguard can be a non-cord reinforcedextruded strip having two or more elastomeric compositions which areco-extruded or hot formed to form the unitary strip. The wrap-aroundtoeguard second end portion includes an apex portion adjacent the turnupextending along the axially outer side of the turnup and may furtherinclude a chafer portion axially outward of the apex portion. Thiscombination of wrap-around toeguard, apex and chafer has threeco-extruded elastomeric compositions forming the unitary strip.

In a preferred embodiment the unitary strip of the wrap-around toeguardhas an uncured cross sectional profile thicker in the mid-region at thelocation wherein the bead core is positioned as compared to the ends.When the preferred embodiment tire is cured the wrap-around toeguard hasa substantially constant gauge thickness as measured around thecircumference of the tire at an axial location or plane passing throughthe bead core.

The bead core has a radial cross-sectional shape which is selected fromthe group consisting of substantially pentagonal, hexagonal, rectangularand circular.

When the bead core is substantially pentagonal, it has the greatestaxial width of the bead core being located radially outwardly of theradially innermost edge of the bead core and with the radially outermostextent of the bead core being the vertex of two of the sides of thepentagon.

DEFINITIONS

As used herein and in the claims:

“Axial” and “axially” are used herein to refer to lines or directionsthat are parallel to the axis of rotation of the tire.

“Bead” means that part of the tire comprising an annular tensile memberwrapped by ply cords and shaped, with our without other reinforcementelements such as flippers, chippers, apexes, toe guards and chafers, tofit the design of the tire rim.

“Belt structure” means at least two layers of plies of parallel cords,woven or unwoven, underlying the tread, unanchored to the bead, andhaving both left and right cord angles in the range from about 17 toabout 27 degrees with respect to the equatorial plane (EP) of the tire.

“Carcass” means the tire structure apart from the belt structure, thetread and the undertread, but including the beads. The carcass plyincludes reinforcing cords embedded in an elastomeric substance and thatthese components are considered to be a single entity. The “main portionof the carcass ply” means the portion of the carcass ply which extendsbetween the bead cores.

“Cord” means one or more of the reinforcement elements, formed by one ormore filaments/wires which may or may not be twisted or otherwise formedand which may further include strands that may or may not be also soformed.

“Crown” means that portion of the tire within the width limits of thetire tread.

“Equatorial plane (EP)” means the plane perpendicular to the tire's axisof rotation and passing through the center of the tire's tread.

“Ply” means a continuous layer of rubber-coated parallel filaments.

“Pneumatic tire” means a laminated mechanical device of generallytoroidal shape (usually an open-torous) having beads, a carcass ply anda tread.

“Radial” and “radially” are used to mean directions radiallyperpendicular from the axis of rotation through the tire.

“Radial-ply tire” means a belted or circumferentially restrictedpneumatic tire in which the carcass ply reinforcements which extend frombead to bead are laid at angles between 75.degree. and 105.degree. withrespect to the equatorial plane of the tire.

“Rivet” means the open space between cords in a layer.

“Section width” means the maximum linear distance parallel to the axisof the tire and between the exterior of its sidewalls when and after ithas been inflated at normal pressure for 24 hours, but unloaded,excluding elevations of the sidewalls due to labeling, decoration orprotective bands.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described by way of example and with reference tothe accompanying drawings in which:

FIG. 1 is one half of a cross-sectional view of the tire according to afirst embodiment of the invention;

FIG. 2 is one half of a cross-sectional view of the tire according to asecond embodiment of the invention;

FIG. 3 is an enlarged fragmentary cross-sectional view of a bead portionof a tire according to a third embodiment of the invention;

FIG. 4 is a cross-sectional view of the wrap-around toeguard of thepresent invention formed as a single material unitary strip;

FIG. 5 is a cross-sectional view of the wrap-around toeguard with anapex portion formed as a unitary strip;

FIG. 6 is a cross-sectional view of the wrap-around toeguard with anapex portion and a chafer portion formed as a unitary strip.

FIG. 7 is a locked bead construction pneumatic tire according to theprior art.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIGS. 1 and 2, there is shown a cross-sectional view oftires 10 according to a first and second embodiment of the presentinvention and FIG. 3 shows a third embodiment of the invention anenlarged fragmentary cross-sectional view of a bead portion and lowersidewall mounted upon a rim.

FIG. 1 shows a cross-sectional view of a tire 10 of the presentinvention. The tire has a pair of bead cores 11 which each comprise aplurality of metallic filaments. The tire 10 is characterized by atleast one carcass ply 12, 14 that extends between the bead cores 11 andat least one turnup portion (12 a, 14 a) anchored around each bead core11. A belt structure 20 having at least two belts 23, 24 is disposedradially outwardly of the main portion of the carcass ply 12, 14 and aground engaging tread portion 15 is disposed radially outwardly of thebelt structure 20. Sidewall portions 16 extend radially inwardly fromthe tread portion to the bead portions. On the axially inner side of thecarcass ply 14, an innerliner 17 may be used. The innerliner 17 consistsof a layer or layers of elastomer or other material that form the insidesurface of the tire and contains the inflating fluid, such as air,within the tire 10. It may be desirable to place additional barriers,reinforcement strips or gum strips (not shown) at suitable locationsbetween the innerliner 17 and main portion of the carcass ply 14 toavoid penetration of rubber through the carcass ply 14 during curing.

A belt structure 20 comprising a plurality of belt plies 23, 24 islocated radially outwardly of the carcass ply 12 or plies 12, 14 in acrown portion of the tire. An elastomeric tread portion 15 is disposedradially outwardly of the belt structure 20. The belt structure has atleast two annular layers or plies 23, 24 of parallel cords, woven orunwoven, underlying the tread 15, unanchored to the bead. Generally, thebelt structure 20 has both left and right cord angles in the range from40 to 15.degree. with respect to the equatorial plane of the tire. It isunderstood that the particular belt structure 20 illustrated in FIGS. 1and 2 and described herein is merely an example used in the preferredembodiment and that a tire designer may employ any arrangement of beltplies in accordance with the performance requirements of the particulartire while still practicing the present invention. For example, in thoseinstances where a larger tire is being constructed for use in a radiallight truck application, three or more belts may be used. In addition,the cords in the belt plies may be rayon, polyester, glass fiber,aramid, steel wire or the like. Preferably, the cord is steel wirehaving a tensile strength of at least (−1400.times.D+4050).times.95%when D is as described above. Particularly preferred is when the cordsare composed of at least one filament having a tensile strength of atleast (−2000.times.D+4050).times.95% when D is as described above.

A tire according to the present invention has a pair of axiallyspaced-apart bead cores 11 which each comprise a plurality of wraps of asingle metallic filament 9. Each of the bead cores 11 has a radialcross-sectional shape which may be substantially pentagonal, hexagonal,rectangular or circular. In the instance where the bead has a radialcross-sectional shape which is substantially pentagonal, the greatestaxial width of the bead core is located radially outwardly of theradially innermost edge of the bead core. As used herein, a “radialcross section” is a cross section taken in a plane which contains theaxis of rotation of a tire or tire and rim assembly. As used herein,“substantially pentagonal” is understood to mean a five-sided crosssection, even though some or all of the sides may be curvilinear ratherthan rectilinear, as in a regular pentagon. The radially outermostextent of the bead core being a vertex of two of the sides of thepentagon and the greatest axial width of the bead core being locatedradially outwardly of the radially innermost edge of the bead core.

The metallic filament 9 used in the bead cores 11 of the illustratedembodiment is 0.05 inch (1.27 mm) diameter steel wire-coated with bronzeto enhance its bonding with rubber. Of course, depending upon the tiresize, other filament diameters could be used in practicing theinvention.

Each of the bead cores 11 has a radial cross-sectional shape which issubstantially pentagonal. For example, in the light truck tire of sizeLT 245/75R16, each of the bead cores may be fabricated having eightradially superposed layers of wraps of said single metallic filament.The number of wraps in each layer, beginning with the radially innermostlayer being 4,5,6,5,4,3,2,1. For other sizes of tires, different numbersof layers, and wraps in each layer may be used.

The cords of the carcass ply 12 or plies 12, 14 are oriented such thatthe tire according to the present invention is what is commonly referredto as a radial. The cords may be steel, rayon, polyester or aramidmaterial or any other suitable cord material.

The cords of the carcass ply 12 or plies 12, 14 intersect the equatorialplane (EP) of the tire at an angle in the range of from 75.degree. to105.degree. Preferably, the cords intersect at an angle of from82.degree. to 98.degree. The preferred range is from 89.degree. to91.degree.

The carcass ply 12 or plies 12, 14 and a toe guard 18 are folded abouteach bead core 11. As mentioned above, the carcass ply 12 or plies 12,14 have a main portion that extends between the bead cores 11 and turnupportions 12 a, 14 a that are folded around the bead cores 11. Theradially outer edge of each turnup portion 12 a is in contact with themain portion of the carcass ply 12 and extends to an end point 12 b 0.5inches (12.7 mm) to 4.0 inches (101.6 mm) radially outward of the beadcore 11 from substantially the middle of the bead core, as measuredalong the main portion of the carcass ply of the tire. Preferably, theturnup portion extends to an end point 12 b 0.5 inches (12.7 mm) to 3.5inches (88.9 mm) radially outward of the bead core 11. The locking in ofthe bead 11 is achieved by the adhesion between the high turnup 12 a orturnups 12 a, 14 a and the main portion of the carcass ply 12, and therestriction of the flange of rim when the tire is mounted on the rim andinflated as can be seen if only one carcass ply 12 is used or if morethan one carcass ply 12, 14 is used the ply 12 closest to the bead core11 will have the ply turnups 12 a, 14 a or at least those portions ofthe turnups contacting that ply directly. As can be seen in FIG. 3, theentire bead construction would be below the top of the rim flange, andthe pentagonal shape of the bead compliments the natural pressuresbetween the tire and the rim in holding the bead on the rim when thetire is inflated. This is particularly true when tires employing highinflation, e.g. 50 psi, use the construction of the present invention.The high turnup, and the consequent high area of adhesive contactbetween the turnup and the main carcass ply, further stabilizes thebead.

A toe guard 18 is associated with each bead core 11. Each toe guard 18has a first-end 18 a and a second end 18 b. Each end 18 a and 18 b isdisposed directly adjacent to the carcass ply 12 in a single ply tire 10or the carcass ply 14 in the two ply tire 10 as shown in FIGS. 1-3. Thefirst end 18 a is located on the axially inner side of the main portionof the carcass ply 14 at a location about 0.4 inches (10 mm) to 3.5inches (89 mm) radially outward of the bead core from substantially themiddle of the bead core. Preferably, the first end 18 a is located onthe axially inner side of the main portion of the carcass ply 14 at alocation A about 0.4 inches (10.16 mm) to 2.0 inches (50.8 mm) radiallyoutward of the bead core. The second end 18 b of the toe guard 18 islocated at a point B ranging from substantially the axially outermostpoint of the bead core 11 to a location about 3.5 inches (89 mm)radially outward of the bead core from substantially the middle of thebead core, as measured along the turnup portion 12 a or 14 a of thecarcass ply 12 or 14. Preferably, the second end 18 b of the toe guard18 is located at a point B ranging from substantially the axiallyoutermost point of the bead core 11 to a location B about 2.0 inches(50.8 mm) radially outward of the bead core 11.

The carcass ply turnup 12 a or turnups 12 a, 14 a is folded about apentagonal-shaped bead bundle or core 11 and locked against the mainportion of the carcass ply 12 by the sidewall 16. In the illustratedembodiment, the carcass ply 12 with turnup portion 12 a terminated at anend point 12 b, 4.0 inches (.apprxeq.101 mm), respectively, radiallyoutward of the bead core 11 as measured along the main portion of thecarcass ply 12 or plies 12, 14 while the lower ply turnup 14 a isterminated at end 14 b, 3.0 inches (approx 76 mm) radially outward ofthe bead core 11 along the main portion of the ply 12 or plies 12, 14.

In the specific illustrated embodiment (see FIG. 1), the axially outerend 18 b of toe guard 18 adjacent the turnup 14 a is located at a pointB 1.6 inches from the midpoint of the bead core 11. The axially innerend 18 a of toe guard 18 is located at point A 1.4 inches (25.5 mm)radially outward of the bead toe 18 c, as measured generallyintersecting and along the main portion of the carcass ply 12 or 14.

The pneumatic tires of the present invention may be designed for variousload ranges. For example, the load ranges may be A, B, C, D or E.

A pneumatic radial ply tire according to FIGS. 1 and 2 was manufacturedin the size LT 245/75R16.

The wrap-around toeguard 18 as illustrated in FIG. 1 is made of a singleelastomeric material or composition 28 and when formed this unitarystrip may be profiled as shown in FIG. 4. As shown in FIG. 4 thewrap-around toeguard may be designed to have a cross-sectional profilethicker in the center 18 c and progressively thinner as it extends awayfrom the bead core 11 toward the ends 18 a and 18 b. This strip ofwrap-around toeguard is non cord reinforced and is preferably formed byextrusion or other shaping means to achieve the desired profile. Unlikeusing multiple wraps of calendered strips of rectangular cross-section,this wrap-around toeguard can be wound 360.degrees. to form an annularloop that has the ends abuttingly joined or cut on a low angle skive andoverlapped while maintaining the general shape or thickness. Preferablythe ends are cut diagonally across the wrap-around toeguard strip 18 toinsure the splice joint is not localized in a single radial plane. Thestrip 18 is applied directly onto the cylindrical unvulcanized carcassof the tire 10 prior to shaping the tire toroidally. The ply 12 isplaced between bead cores 11 and the wrap-around toeguards 18 and theturnups 12 a, 14 a with the second ends 18 b are folded over the beadcores 11 and stitched to the main portion of the carcass prior to beingshaped toroidally and prior to applying the belts 23, 24, and the tread15.

In FIG. 2 the second embodiment tire 10 is shown with basically the samecomponents, however, the wrap-around toeguard 18 is formed with atoeguard portion 28 and an apex portion 29. The apex portion 29 liesadjacent the turnup 12 a or 14 a depending on the number of plies usedextending from the vortex of the bead core a distance of less than 3.5inches, preferably about 2.4 inches along the turnup. The apex materialis stiff preferably having a greater than a shore of 40 stiffnessmodules. Both the apex portion 29 and the wrap-around toeguard portion28 are formed and shaped together while hot using co-extrusion orcalendered hot forming techniques to achieve the desired profile asillustrated in FIG. 5. The carcass ply 12 or plies 12, 14 are placed onthe wrap-around toeguard 18 prior to placing the bead core 11 on a tirebuilding drum not shown. The assembly is then folded over the bead core11 thereby forming the turnup ends 12 a, 14 a prior to shaping the tire10 toroidally and prior to adding the belts 23, 24 and tread 15 andmolding the tire in a curing press.

In a third embodiment the wrap-around toeguard 18 may include a chaferportion 27 made of a third material of elastomeric composition. Thispreferred embodiment has three distinct rubber or elastomericcompositions all hot formed or co-extruded to form a unitary non cordreinforced strip of rubber. This chafer portion 27 as shown in FIG. 3occupies a space adjacent to where the flange of the rim to which thetire 10 is to be mounted would rub against the tire.

This ability to form all these components into a single wrap-aroundtoeguard piece 18 forming one loop both improves the accuracy ofplacement of the material as well as eliminates the inherentnon-uniformities created by using multiple windings of gum strips as wasdescribed in the prior art tire of U.S. Pat. No. 6,719,030.

An important feature of the present invention is the fact that therubber components 27, 28, 29 are formed and shaped together while hotsuch as in done in a co-extrusion process or by hot forming in calenderrollers as described in U.S. Pat. No. 6,126,780 to form a unitary strip18 as an intermediate article of manufacture. In this way the strip 18can be most accurately produced and positioned onto the tire carcassduring assembly. This further enhances the ability to profile the shapeof the strip 18 to achieve a precise amount of uniform rubber directlyunder and around the bed core 11.

A further advantage is wrap-around toeguard 18 can be made replacingthree separate strips of gum, toeguard, chafer and apex and when usingco-extrusion or hot forming while maintaining the distinct ability touse specific materials designed for each portion of the toeguard 28, thechafer 27 and the apex 29. In each embodiment the wrap-around toeguardemploys non-cord reinforced materials. In some embodiments the specificelastomers used in the manufacture of the toeguard 18 may include shortfibers or other fillers for enhanced stiffness or toughness.

Variations in the present invention are possible in light of thedescription of it provided herein. While certain representativeembodiments and details have been shown for the purpose of illustratingthe subject invention, it will be apparent to those skilled in this artthat various changes and modifications can be made therein withoutdeparting from the scope of the subject invention. It is, therefore, tobe understood that changes can be made in the particular embodimentsdescribed which will be within the full intended scope of the inventionas defined by the following appended claims.

1. A pneumatic tire having a pair of locked in beads, the tirecomprising: a pair of axially spaced apart annular bead cores; at leastone cord reinforced carcass ply wrapped around each bead core and havingat least one pair of carcass ply turnups contiguous with the at leastone carcass ply from a radially outermost extent of the bead core to aradially outer end or ends of the at least one pair of carcass plyturnups; a wrap-around toeguard associated with each bead core, eachwrap-around toeguard being a non-cord reinforced elastomeric unitarystrip wound 360° in a single annular loop and having first and secondends wherein each end thereof is disposed directly adjacent to saidcarcass ply, said first end being located on the axially inner side ofthe carcass ply at a location about 0.4 inches (10 mm) to 3.5 inches (89mm) radially outward of the bead core as measured along the carcass plyand said second end being adjacent the turnup of the carcass ply locatedat a point ranging from substantially the axially outermost point of thebead core to a location about 3.5 inches (89 mm) radially outward of thebead core as measured along the turnup of the carcass ply, and whereinthe first end and second end of the toeguard is a shorter radialdistance from said bead core than the radially outermost end of the atleast turnup of the carcass ply; and wherein the wrap-around toeguard isa non-cord reinforced unitary extruded strip formed of a singleelastomeric composition having a shore D hardness greater than
 40. 2.The pneumatic tire of claim 1 wherein a radially inner portion of thesecond end of the wrap-around toeguard extends from the bead core andthe turnup axially outwardly to the outer surface tire.
 3. The pneumatictire of claim 1 wherein a radially outer portion of the second end ofthe wrap-around toeguard is overlapped by a sidewall portion of thetire.
 4. The pneumatic tire of claim 1 wherein said bead core has aradial cross-sectional shape which is selected from the group consistingof substantially pentagonal, hexagonal, rectangular and circular.
 5. Thepneumatic tire of claim 1 wherein said bead core is substantiallypentagonal with the greatest axial width of the bead core being locatedradially outwardly of the radially innermost edge of the bead core andwith the radially outermost extent of the bead core being the vertex oftwo of the sides of the pentagon.
 6. The pneumatic tire of claim 1wherein said radially outermost end of one of said at least one turnupsis in contact with the carcass ply and extends to an end point 0.5inches (12.7 mm) to 3.5 inches (88.9 mm) radially outward of the beadcare, as measured along the carcass ply of the tire.
 7. The pneumatictire of claim 1 wherein said first end of said wrap-around toeguard islocated on the axially inner side of the carcass ply at a location about0.4 inches (10.16 mm) to 2.0 inches (50.8 mm) radially outward of thebead core.
 8. The pneumatic tire of claim 1 wherein said second end ofsaid wrap-around toeguard is located at a point ranging fromsubstantially the axially outermost point of the bead core to a locationabout 2.0 inches (50.8 mm) radially outward of the bead core as measuredalong the turnup portions of the at least one carcass ply.